The photoactive compound is a material that producing the atom or molecule which chemically carries activity by absorbing light to be decomposed, and is widely used as the photosensitive composition. As examples of the material carrying the chemical activity, there are the acid or the base, the radical and the like. In particular, the photoactive compound that produces the radical may be used in conjunction with an acryl group that causes the polymerization reaction in conjunction with the radical and may be used for the purpose of improving the strength of the coated film. As the photosensitive composition for this purpose, there is ink for inkjet or a transparent or colored protection film such as automobiles, mobile phones or the like. In addition, according to the polymerization reaction by light, it is applied to the photosensitive resin composition for the optical etching method using a phenomenon in which the solubility is reduced. As a representative example thereof, there are photopolymerization types of photosensitive composition that is used to produce a color filter of a liquid crystal display device or a photosensitive composition for a resin black matrix.
In general, the photosensitive composition comprises a polymer resin compound, a polymerizable compound that comprises an ethylenically unsaturated bond, a solvent, and a photoactive compound.
As a general example of the photoactive compound that is used in the photosensitive composition, various types of derivatives such as a acetophenone derivative, a benzophenone derivative, a biimidazole derivative, an acylphosphine oxide derivative, a triazine derivative, an oxime ester derivative and the like are known. Among them, in the case of the oxime ester derivative, since it absorbs the ultraviolet rays, it hardly shows the color, there are advantages in that the efficiency of the radical generation is high, and the stability in the composition is excellent.
Japanese Unexamined Patent Application Publication Nos. 61-118423, 1-68750, and 3-4226 disclose the use of the α-oxo oxime derivative as a photoresist photoinitiator for photoimaging and print wiring plates, and a document (Opt. Eng. 24 (1985) 808; J. Opt. Eng. 27 (1988) 301) discloses the use of the α-oxo oxime derivative as a holography photoinitiator.
In particular, in respects to the photoinitiator of the oxime ester structure, U.S. Pat. No. 4,590,145 discloses a photoinitiation system using thiooxanthone and the oxime ester compound, and U.S. Pat. No. 4,255,513 discloses an oxime ester photoinitiation system using p-dialkylaminobenzene as a synergist.
U.S. Pat. No. 5,776,996 discloses a photoinitiator using a photopromoting pigment, a titanocene compound, and β-aminooxime, and U.S. Pat. No. 6,051,367 discloses an oxime ether photoinitiator in which an ethylenically unsaturated group capable of participating in the photopolymerization is comprised in a molecule structure. WIPO 00/52530 and Germany Unexamined Patent Application Publication No. 199 28 742 A1 disclose oxime ether, oxime ester, in particular, a photosensitive composition using oxime sulfonate as a photoinitiator.
WIPO 02/100903 A1 discloses an oxime ester compound having the structure combined with alkyl acyl ketone, diaryl ketone or ketocumarine.
In addition to these, in respects to the oxime ester structure, U.S. Pat. No. 4,202,697 discloses that it is used as the etch resist, and U.S. Pat. No. 6,001,517 discloses that it is used as a photosensitive thermosetting accelerator in a posi-type photosensitive composition.
However, in the used oxime derivative compound, the compound that was developed at an early step has the low photoinitiation efficiency, and in the case of when the color property is excellent, it is not effective to absorb the UV light source. In the compounds that are announced after 1990's latter half, the photoinitiation efficiency is very improved, but they cannot sufficiently satisfy the reduced process time that is currently enhanced. In particular, since the concentration of the pigment is high or the thick film that has the thickness of the coating film of 2.5 μm or more is not sufficiently cured, it is difficult to form a fine pattern, and the formed pattern cannot show the required size and the mechanical strength. In addition, since a difference between solubilities in respects to various solvents is large, there are many cases of when its use is limited.
Therefore, the development for a photoactive compound that is capable of improving the solubility in respects to an organic solvent, efficiently absorbing ultraviolet rays, and improving the reactivity in respects to light, that is, the sensitivity is required.